Analysis of DNA from Ethnoarchaeological Stone Scrapers

Analysis of DNA residues on stone tools provides a direct method of determining what the tools were used on. However, little is known about the taphonomy of DNA on tools. The discovery of present-day, stone-tool using hide workers in Ethiopia therefore provides a unique opportunity to study the survival and authenticity of DNA residues on stone tools. We collected stone scrapers from contexts ranging from excavated to confirmed use, as well as unused scrapers to test for the presence of DNA residues. We amplified segments of the mitochondrial genome with PCR to determine which animal species a tool was used on. We were able to recover authentic DNA from scrapers of known use and from a subset of excavated scrapers. We did, however, also obtain DNA unrelated to the use of the tools. Thus, caution must be used when interpreting results of DNA analysis of stone tools.     

DNA AND PROTEIN RECOVERY FROM WASHED EXPERIMENTAL STONE TOOLS*

Traces of protein and DNA are preserved on stone tools used to process animals. Previous research documents the identification of protein residues from tools sonicated in 5% ammonium hydroxide, but it remains untested whether the same treatment yields useable DNA. In this study we report both DNA and protein recovery using 5% ammonium hydroxide from residues on stone tools. We extracted 13‐year‐old residues from experimentally manufactured stone tools used to butcher a single animal. We also show that surface washing procedures typically used to curate stone tools remove only a small fraction of the DNA and protein deposited during animal butchery.     

What novice knappers have to learn to become expert stone toolmakers

The aim of this paper was to determine what technical gestures must be learned in order to produce stone tools. To identify these gestures, we compared the performance of expert knappers and complete novices. We hypothesised that the differences between novices and experts would indicate which technical gestures experts had learned to successfully produce stone tools. Participants were video recorded while attempting to produce a crude handaxe. The recordings were analysed according to ethological methods used to study animal and human behaviour. The knapping performance of each participant was segmented and scored into units in order to identify the technical gestures being used. The results showed considerable differences between experts and novices in three technical gestures: the type of percussion support, the position of the blank and the angle of blow. Therefore, these three technical gestures appear to be crucial in learning to knap stone at the level of bifacial stone toolmakers. By studying how modern knappers gradually master these three technical gestures we may begin to understand how stone knapping is acquired, how bifacial stone tools emerged and what cognitive challenges early handaxe makers had to face.     

Des coquillages… outillages des Ichtyophages? Mise en évidence d'industries sur Veneridae,du Néolithique à l’âge du Fer (Yémen,Oman, E.A.U.)

From Yemen to the Arabian/Persian Gulf the coastal societies of Arabia developed an industry utilising bivalve shells (Veneridae). From the Neolithic to the Iron Age these shells were transformed into knives or scrapers, the latter sometimes having a characteristic notch. The majority of these tools are manufactured from the left valve, probably selected by right-handed people. The shell tools are very standardised and did not replace stone tools; they were probably intended for specific and complementary uses. In Arabia this industry constitutes a specific element of the material culture of the Ichthyophagi .     

Stone Tool Production of the Longshan Culture at the Liangchengzhen Site in Rizhao of Shandong

The manufacture of stone tools was one of the most important craft production activities in prehistoric human society. Previously, lack of sound evidence had made it too early to confirm whether or not stone tool production during the Longshan cultural period had already transformed from a primitive self-sufficient household mode of production to a specialized mode of production. Excavation of the site of the Longshan cultural site at Liangchengzhen in Rizhao, Shandong from 1998–2001 through meticulous field methods such as sieving and floatation yielded a large number of lithic reduction tools, ranging from grinding stones, stone hammers, and polishing stones to raw materials, semi-finished products, and lithic debitage of various sizes, resulting from the lithic reduction process. This excavation suggests that the Liangchenzhen site was a settlement site where the complete process of lithic reduction was practiced. Through comparison with contemporary large-scale excavated sites of the Longshan culture, it is suggested that the Area 1 at the Liangchengzhen site was a lithic reduction locality with a relatively high degree of specialization which was used for hundreds of years. It is possible that stone tool production had already advanced to a stage of relatively high specialization during the Longshan cultural period in the Haidai region.     

Recovery of Protein and DNA Trapped in Stone Tool Microcracks

Microcracks produced during the manufacture of stone tools may harbour ancient biological residues. Our studies test this hypothesis using light, scanning electron, fluorescence, and confocal microscopy to characterize microcracks produced in obsidian microblades by pressure flaking. Cell-sized fluorescent latex beads penetrated microcracks to depths exceeding 50 μm below the microblade surface. Fluorescently labelled blood protein and DNA were trapped in microcracks within 5 min of exposure. Washing artifacts with water did not remove blood residues from microcracks. However, 60–80% of trapped blood protein and DNA were released by an 18-hour incubation in 4M guanidine hydrochloride or by sonication in 5% ammonium hydroxide. These experiments suggest that residues trapped in artifact microcracks represent an important and often overlooked source of ancient DNA and protein.     

Assessing the reliability of pRIA for identifying ancient proteins from archaeological contexts

The use of immunological techniques for identifying the origin of proteins and inferring foodstuffs exploited by prehistoric occupations has been conducted for several decades. Cases of experimental laboratory and archaeological studies have shown the potential of these techniques for reliable results. However, very few of these case studies employ archaeological sites that have excellent preservation and high-resolution spatial contexts between identifiable faunal remains, features, and stone tools. We present an assessment of the identification reliability of one immunological technique, protein radioimmunoassay (pRIA), using faunal remains and stone tools from two sites from arctic and subarctic contexts. The results of this research indicate that, even in contexts with excellent preservation, the identifications produced by the pRIA technique are subject to misidentification and cross-reactions due to diagenetic alteration of proteins. We propose a higher minimum reaction value (percent binding of labeled antibody) that mitigates these effects, and renders the pRIA results more reliable for ancient, poorly preserved organic remains.     

Animal DNA in PCR reagents plagues ancient DNA research

Molecular archaeology brings the tools of molecular biology to bear on fundamental questions in archaeology, anthropology, evolution, and ecology. Ancient DNA research is becoming widespread as evolutionary biologists and archaeologists discover the power of the polymerase chain reaction (PCR) to amplify DNA from ancient plant and animal remains. However, the extraordinary susceptibility of PCR to contamination by extraneous DNA is not widely appreciated. We report the independent observation of DNA from domestic animals in PCR reagents and ancient samples in four separate laboratories. Since PCR conditions used in ancient DNA analyses are extremely sensitive, very low concentrations of contaminating DNA can cause false positives. Previously unidentified animal DNA in reagents can confound ancient DNA research on certain domestic animals, especially cows, pigs, and chickens.     

Developing FTIR Microspectroscopy for the Analysis of Animal-Tissue Residues on Stone Tools

The analysis of microscopic residues on stone tools provides one of the most direct ways to reconstruct the functions of such artifacts. However, new methods are needed to strengthen residue identifications based upon visible-light microscopy. In this work, we establish that reflectance Fourier-transform infrared microspectroscopy (FTIRM) can be used to document IR spectra of animal-tissue residues on experimental stone tools. First, we present a set of reflectance FTIRM standards for the most commonly identified animal-tissue residues on stone tools: skin, meat, fat, hair, blood, feather barbules, fish scales, and bone. We provide spectral peak assignments for each residue and demonstrate that high-quality reflectance FTIRM spectra can be generated under ideal circumstances. Second, we document the spectra for these residues when they are located on a stone substrate such as flint or obsidian. We discuss procedures for correcting spectra that are affected by specular reflection and explain the effects of spectral interference from the stone. Our results show that reflectance FTIRM is sensitive to small intra-sample differences in composition. This means that it will record the effects of decomposition in ancient residues. The methodological developments we present here will help lithic residue analysts incorporate in situ reflectance FTIRM into their analysis protocols to strengthen identifications.     

Testing the Efficiency of Simple Flakes,Retouched Flakes and Small Handaxes During Butchery

Handaxes, simple flakes and retouched flakes are three types of stone tools whose adaptive advantages are highly debated. Interpretations of these technologically different tools suggest that their adequacy for butchery is uneven. Although some experimentation has been made in this regard, further research is needed to understand which of these tool types are more efficient for butchery, thus granting adaptive advantages to the hominins who used them. The present experimental work shows that small handaxes provide higher return rates in butchery activities than simple and retouched flakes. Efficiency (measured in time) is significantly positive in handaxes compared to the other tools when defleshing. In contrast, when comparing the three stone tool sets (simple flakes, retouched flakes and handaxes), the return values obtained for disarticulation are very similar. This study also shows that cut marks do not occur randomly and are less stochastic than previously assumed. Defleshing leaves a preferential cluster of cut marks on mid‐shafts from long bones and even on these sections, depending on element type, patterns are statistically demonstrable.     

Sequence Analysis of Grip and Manipulation During Tool Using Tasks: a New Method to Analyze Hand Use Strategies and Examine Human Specificities

Different factors may have coevolved with hand dexterity such as bipedalism, brain enlargement, language, and the production and use of stone technology. Prehistoric stone tools are thus probably one of the key elements to examine the origin and evolution of these essential functions during human evolution. To gain a better understanding of the variability of traces resulting from use found on stone tools or on the body of the user, to better infer past archaeological tools, and to assess what the tool-using human hand specificities are, it is essential to investigate and describe tool manipulation itself. Studies investigated this question but either focused on static finger postures during grasping, or involved complex kinematic model of the coordination of the fingers necessitating the pose of many markers on the hand excluding the application of the method on non-human species. Here, we propose a new method to describe and quantify the dynamic strategies of tool grip and manipulation without the need of markers. We tested this method on five human subjects who had to make bamboo points using flint flakes. Time-based sequence analysis allowed identifying and describing both consistency and variation among users and types of use depending on the observed variable (e.g., hand contact areas, repositioning). The method proved to be efficient and, to our knowledge, is the only available method to describe and quantify with such detailed level grip and manipulation as dynamic process in both human and non-human primates without high technical constraint.     

The limits of biomolecular palaeopathology: ancient DNA cannot be used to study venereal syphilis

To determine whether ancient DNA (aDNA) can be used to study the palaeopathology of venereal syphilis, we carried out a comprehensive analysis of the preservation of human and pathogen DNA in a set of 46 bones of various ages, most of which displayed osteological indications of the disease. Bones came from seven English cemetery sites that were in use during the 9th–19th centuries. Twelve of the 46 bones consistently yielded mitochondrial DNA (mtDNA) sequences after replicate polymerase chain reactions (PCRs), and a further 13 bones yielded mtDNA sequences with less reproducibility. The sequence data enabled tentative mitochondrial haplogroups to be assigned to nine of the bones, and the identities and frequencies of these haplogroups were compatible with the geographical origins of the bones. Twenty-one bones consistently gave negative results with all mtDNA PCRs, indicating that at least these bones were not contaminated with modern human DNA, and those bones that gave positive results only yielded one sequence each, again suggesting that widespread modern contamination had not occurred. Mycobacterium tuberculosis sequences were obtained from seven bones, including three of five bones with tuberculous lesions. The cloned and direct sequences obtained from both the mtDNA and M. tuberculosis PCR products showed features typical of degraded aDNA. All of these results suggest that at least some of the 46 bones that we studied were suitable for aDNA analysis. All 46 bones were tested with nine different treponemal PCRs, each optimised to give a detection limit of ≤5 genomes. Although various bones gave PCR products of the expected size with one or more of these PCRs, sequencing showed that none of these products were authentic treponemal amplicons. Our failure to detect treponemal DNA in bones that were suitable for aDNA analysis, using highly sensitive PCRs, suggests that treponemal DNA is not preserved in human bone and that it is therefore not possible to use aDNA analysis to study venereal syphilis. Any past or future paper claiming detection of treponemal aDNA should therefore be accompanied by a detailed justification of the results.     

The technology of Stone Age colonization: an empirical,regional-scale examination of Clovis unifacial stone tool reduction,allometry, and edge angle from the North American Lower Great Lakes region

There is now broad consensus that the appearance of Clovis in Northeastern North America (Great Lakes, New England) represents a colonization pulse into recently deglaciated landscapes. Due to the increased resource uncertainty that comes with colonizing unfamiliar landscapes, it was hypothesized that the majority tool component of Clovis assemblages, unifacial stone tools, should have been knapped on tool blanks possessing the design properties of longevity and functional flexibility to facilitate exploration mobility and guard against the absence of toolstone sources in the new landscape. These properties are optimized by large, flat flakes, possessing large surface area relative to flake thickness. Since discarded and, at times, exhausted unifacial stone tools do not preserve the original dimensions of the blank upon which they were created – necessary items for a true test of blank morphology selection – this study presents a set of predictions for inferring whether Clovis unifacial stone tool blanks were selected for the properties of longevity and functional flexibility based on evidence that Clovis people actually capitalized on those properties. Due to the nature of Clovis unifacial stone tools, tool size was of necessity used as a proxy for tool reduction, on the grounds that smaller tools are more likely to have been resharpened than larger tools, at least in the case of unifacial flake tools. The results showed that less resharpened tools possessed flatter, less spherical shapes than the more resharpened tools, which possessed more globular, spherical shapes, suggesting Clovis foragers exploited the retouch potential afforded by the larger, flatter blanks. Edge angles showed no relationship with tool reduction, suggesting that Clovis foragers exploited the functional flexibility afforded by flatter blanks by adjusting the edge angle to be either higher or lower as needed. These results are consistent with the notion that human colonizers, who did not know the abundance or location of stone outcrops prior to settling an unfamiliar territory, not only “geared up” before leaving a stone source, but geared up as efficiently as possible by carefully selecting the blanks they chose to carry. Broader implications for such careful unifacial stone tool blank selection are discussed.     

Experiments with Lithic Tools: Understanding Starch Residues from Crop Harvesting

Stone knives were used widely in Neolithic East Asia, presumably in the harvesting of grain crops, but their function has not been clearly understood due to the lack of study of residues from these tools. To address this issue, starch grain analysis was employed to study the residues on the surface of ancient stone knives and large amounts of starches were recovered. The sources of these starches, however, were not well understood, because harvesting of crops involves the cutting of stems rather than direct contact with starchy seeds. To determine whether harvesting could deposit these types of residues, we designed a simulation experiment using stone flakes to harvest ears of wheat, rice and foxtail millet, then analysed the residues on both the flakes and in the plant tissues. A large number of starch grains were found in the stems, including both typical morphotypes from seeds and newly described types that occur only in stems, which can be used as indicators of harvesting. Our study demonstrates that starch grains from residues on the surfaces of archaeological stone knives can indicate not only that the tools were used to harvest ears, but also the type of crops harvested.     

High-Tech Foragers? Folsom and Later Paleoindian Technology on the Great Plains

Archaeologists generally argue that early (ca. 11,000–8000 B.P. populations on the North American Great Plains moved over very large areas, relying on sophisticated, biface-based flaked stone technology and on extensive resharpening and recycling of tools to cope with unpredictable access to raw material sources. This paper reviews the development of this reconstruction and considers the degree to which data from assemblages of Paleoindian flaked stone tools support it. Published information implies that patterns of raw material use vary greatly over the Plains, that bifaces were not the centerpiece of Paleoindian technology, that there are no published efforts to document an unusual degree of resharpening or recycling, and that the data that are available on these topics do not suggest that either was important. Detailed analysis of one assemblage, from the Allen site in southwestern Nebraska, carried out with these issues in mind, shows similar patterns. The great difference between what the literature says about Paleoindian technology and the documented character of that technology suggests that Paleoindian lifeways were far more variable than current discussions suggest.     

Toolstone constraints on knapping skill: Levallois reduction with two different raw materials

Lithic raw material constraints are widely assumed to be a determining factor of flaked stone tool morphology, but this assumption remains largely untested. We conducted a controlled experiment to determine whether a knapper’s growing replication skills would be hindered if the toolstone used was switched from large flakes of an easily worked chert to nodules of less tractable one. Two batches of Preferential Levallois cores were knapped, an earlier series made from standardised large flakes of sediments dominated by chalcedonic quartz followed by a more challenging one using variably-shaped, cortical nodules of microcrystaline quartz that varies in the completeness of quartz replacement of calcite and dolomite. Skill level markers were designed to measure the knapper’s ability to achieve a series of set goals. These were quantified and subjected to statistical testing. In all but one test, significant increases in skill could be detected from the earlier to the later batch of reductions, despite the drop in toolstone quality. Significant improvements in the consistency of the knapper’s output could also be detected. However, the switch to a more challenging, nodular chert did require extra shaping, which resulted in more waste. This masked visible progress towards producing a less costly core. Overall, our results do not support the assumed primacy of toolstone constraints over other factors in influencing the morphology of flaked stone tools.     

劣化石刻表层生物矿化加固材料的探索性研究

许多濒危石质文物表层劣化现象严重。但是,以往使用的表层加固材料很难令人满意,探索新的疏松岩石表层加固材料已是当务之急。由于天然生物矿化物耐候性优越,与基底岩石相容性良好,具有较好的加固作用,本工作依据生物矿化的原理,以不同生物大分子溶液作为有机模板,分别控制草酸钙、磷灰石和碳酸钙过饱和溶液于室温下在疏松岩石仿制样品的表层及孔隙内结晶生长。通过抗压强度、表面硬度和耐水浸泡等试验进行了加固效果评价,以考察仿生物矿化材料对含钙疏松岩石的加固能力。实验结果表明,仿生合成的生物矿化材料均具有一定的加固效果,其中以磷灰石仿生矿化材料的加固强度最大,以硫酸软骨素为模板的加固效果为佳。并且,在考察的3种加固方式中,以"直接混合"的加固强度更好,以"表面渗透"的耐水浸泡能力更强。本工作为开发濒危石质文物表层加固材料提供了新的思路。     

Sickle blade life-history and the transition to agriculture: an early Neolithic case study from Southwest Asia

In Southwest Asia, sickle blades first appear early in the sequence of the transition to agriculture. In the past, detailed qualitative research on silica bearing blade stone tools focus on the characterization of use-wear traces such as polish types and accrual rates. In this paper we approach the study of sickle blades slightly different, choosing to examine tool life-history by developing a method to quantitatively estimate harvesting intensity. The method centers on an experiment of cutting cereal stalks and measuring stone blade edge thickness under a scanning electron microscope as a proxy for cutting time. We end with regressing the experimental results to provide an estimation of how intensively archaeological sickle blades recovered from the site of Dhra’, Jordan were used for harvesting. The results, while preliminary, enable an initial interpretation of sickle blades as important tools with long use-life histories during the early Neolithic in the Southern Levant.     

Swept under the rug: the problem of unacknowledged ambiguity in lithic residue identification

Microscopic analysis of organic residues on stone tools is used to interpret prehistoric stone tool functions. The morphology of some residues can be difficult to interpret, yet this ambiguity is rarely acknowledged in the literature. Our research seeks to understand the nature of this ambiguity by objectively identifying ambiguous residues in our reference collection. We trained four archaeologists in residue analysis using one part of our reference collection, then tested their ability to identify sixty-eight residues in another part of the same collection. Forty-eight of the residues in the test (70%) were correctly identified by three or all four subjects. We considered the remaining twenty residues, which were correctly identified by two or fewer of the subjects, to be ambiguous. These are most often in the hide-scraping, bone-scraping, and hardwood-scraping (macerated) categories, and tend to have an atypical morphology which falls in the range of variability of another residue category. Some of these residues also have optical properties which make them more difficult to image than others. We explore the potential for scanning electron microscopy (SEM) to improve residue identification in a second test. This test shows a modest improvement in identification success rates of ambiguous residues when SEM images are included. We conclude that while images from different types of microscopes can improve reliability of identification, some residues will always be ambiguous. Rather than being ignored, these ambiguities should be brought to light, closely examined, and published as such.